Bicycles are vehicles having two wheels mounted, one behind the other, to a frame upon which the rider sits. The bicycle is conventionally driven by the rotation of pedals connected to a crankarm, which in turn rotates a front sprocket. The front sprocket is connected to the rear wheel by a chain and rear sprocket, so that the rotation of the pedals forces rotation of the rear wheels. The front wheel is mounted to a front fork that, in turn, is connected to movable handle bars, permitting the front wheel to be turnably steered by the turning of the handle bars.
One form of bicycle is the recumbent bicycle. In the recumbent bicycle, the rider will sit closer to the ground on a bench-type seat, in a truly sitting position with the legs extending forwardly. The pedals and front sprocket are well in front of the rider, but are pedaled in the same fashion as normal bicycles for the propulsive power. The recumbent bicycle has important advantages over the standard bicycle in reduced wind resistance, better downhill performance, and increased comfort of the bench seat over the saddle seat (of regular bicycles).
The recumbent bicycle has been used in bicycle speed trials and in specialty racing, but has not generally received the widespread acceptance of the standard bicycle, despite its many advantages. Typically, recumbent bicycles must be custom designed, generally to the size of the user. As a result, the cost associated with the manufacture of such recumbent bicycles is very expensive. There has been little standardization of design. Currently, recumbent bicycles are made by a large number of very small companies that manufacture recumbent bicycle designs of many forms and fashions.
Typically, conventional recumbent bicycles use a similar frame tube as is used in conventional bicycles. This frame tube is a tube having an annular cross-section. As a result of the annular nature of such tubes, it becomes very difficult to mount the various components onto the frame of the bicycle. It is also very difficult to elongate or to retract the components after they are assembled on such annular tubing. This annular tubing does not provide a convenient means for reinforcement where the forces are greatest. Conventional recumbent bicycles often break, or become damaged, when excessive forces are imparted onto the frame.
In the conventional construction of recumbent bicycles, the various components of the recumbent bicycle must be welded to the frame. The welding of such components to the frame generally makes the components non-removable and non-adjustable. Additionally, the very act of welding components to the frame of the recumbent bicycle will cause a weakness in the metallurgy and mechanical strength of the frame. As such, it would be desirable to avoid the welding of the components to the main structure of the frame.
Furthermore, conventional recumbent bicycle designs are of relatively heavyweight construction. Such heavyweight construction is necessary so as to properly support the forces imparted by the central positioning of the rider between the wheels of the recumbent bicycle. Additional reinforcements are necessary to the structure of the recumbent bicycle than are used on conventional bicycles. These additional structural components add a great deal of weight to the frame.
It is an object of the present invention to provide a frame for a recumbent bicycle that allows for the mechanical attachment of components to the frame.
It is another object of the present invention to provide a recumbent bicycle frame that facilities the installation of reinforcements onto the frame.
Is it a further object of the present invention to provide a recumbent bicycle frame which allows for the adjustable positioning of the various components of the bicycle.
It is still a further object of the present invention to provide a recumbent bicycle frame that is easy to assemble, easy to use, and relatively inexpensive.
It is another object of the present invention to provide a frame that has greater torque stability.
It is still another object of the present invention to provide a recumbent bicycle frame that is relatively lightweight.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.